refactor

src/database/Database.js

@@ -1,15 +1,12 @@
 import { IndexedDBEngine } from './IndexedDBEngine'
 import { assertNonEmptyString } from './utils/assertNonEmptyString'
+import { assertETag } from './utils/assertETag'
+import { assertEmojiBaseData } from './utils/assertEmojiBaseData'
+import { assertNumber } from './utils/assertNumber'
 
 const DEFAULT_DATA_SOURCE = 'https://cdn.jsdelivr.net/npm/emojibase-data@5/en/compact.json'
 const DEFAULT_LOCALE = 'en'
 
-function checkETag (eTag) {
-  if (!eTag) {
-    throw new Error('lite-emoji-picker expects the dataSource server to return an eTag header')
-  }
-}
-
 export class Database {
   constructor ({ dataSource = DEFAULT_DATA_SOURCE, locale = DEFAULT_LOCALE } = {}) {
     this._dataSource = dataSource
@@ -32,26 +29,22 @@ export class Database {
         return
       }
       const eTag = headResponse.headers.get('etag')
-      checkETag(eTag)
+      assertETag(eTag)
       if (await this._idbEngine.hasData(this._dataSource, eTag)) {
         return // fast init, data is already loaded
       }
     }
     const response = await fetch(this._dataSource)
     const emojiBaseData = await response.json()
-    if (!emojiBaseData || !Array.isArray(emojiBaseData)) {
-      throw new Error('Expected emojibase data, but data was in wrong format: ' + emojiBaseData)
-    }
+    assertEmojiBaseData(emojiBaseData)
     const eTag = response.headers.get('etag')
-    checkETag(eTag)
+    assertETag(eTag)
 
     await this._idbEngine.loadData(emojiBaseData, this._dataSource, eTag)
   }
 
   async getEmojiByGroup (group) {
-    if (typeof group !== 'number') {
-      throw new Error('group must be a number, got: ' + group)
-    }
+    assertNumber(group)
     await this._readyPromise
     return this._idbEngine.getEmojiByGroup(group)
   }

src/database/utils/assertETag.js

@@ -0,0 +1,5 @@
+export function assertETag (eTag) {
+  if (!eTag) {
+    throw new Error('lite-emoji-picker expects the dataSource server to return an eTag header')
+  }
+}

src/database/utils/assertEmojiBaseData.js

@@ -0,0 +1,5 @@
+export function assertEmojiBaseData (emojiBaseData) {
+  if (!emojiBaseData || !Array.isArray(emojiBaseData) || !emojiBaseData.length || !emojiBaseData[0].unicode) {
+    throw new Error('Expected emojibase data, but data is in wrong format')
+  }
+}

src/database/utils/assertNumber.js

@@ -0,0 +1,5 @@
+export function assertNumber (number) {
+  if (typeof number !== 'number') {
+    throw new Error('expected a number, got: ' + number)
+  }
+}